move header into track.output.format object and then use it in the decoder create method.

This doesn't make a stateless decoder but it is a step in the right direction.
Note that subtitles are not rendering. Is there something wrong with the timecodes?

build.gradle

@@ -19,7 +19,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.2.1'
+        classpath 'com.android.tools.build:gradle:2.2.3'
         classpath 'com.novoda:bintray-release:0.3.4'
     }
 }

demo/src/main/assets/media.exolist.json

@@ -352,6 +352,10 @@
     "name": "Misc",
     "samples": [
       {
+        "name": "Watashi ga Motete Dousunda - 01 SSA",
+        "uri": "http://192.168.1.133:8080/Watashi ga Motete Dousunda - 01.mkv"
+      },
+      {
         "name": "Dizzy",
         "uri": "http://html5demos.com/assets/dizzy.mp4"
       },

library/src/main/java/com/google/android/exoplayer2/Format.java

@@ -305,9 +305,18 @@ public final class Format implements Parcelable {
   public static Format createTextSampleFormat(String id, String sampleMimeType, String codecs,
       int bitrate, @C.SelectionFlags int selectionFlags, String language,
       int accessibilityChannel, DrmInitData drmInitData, long subsampleOffsetUs) {
+    return createTextSampleFormat(id, sampleMimeType, codecs, bitrate, null, selectionFlags, language,
+            NO_VALUE, drmInitData, subsampleOffsetUs);
+  }
+
+  public static Format createTextSampleFormat(String id, String sampleMimeType, String codecs,
+      int bitrate,
+      List<byte[]> initializationData,
+      @C.SelectionFlags int selectionFlags, String language,
+      int accessibilityChannel, DrmInitData drmInitData, long subsampleOffsetUs) {
     return new Format(id, null, sampleMimeType, codecs, bitrate, NO_VALUE, NO_VALUE, NO_VALUE,
         NO_VALUE, NO_VALUE, NO_VALUE, null, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE, NO_VALUE,
-        NO_VALUE, selectionFlags, language, accessibilityChannel, subsampleOffsetUs, null,
+        NO_VALUE, selectionFlags, language, accessibilityChannel, subsampleOffsetUs, initializationData,
         drmInitData, null);
   }
 

library/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java

@@ -1110,13 +1110,8 @@ public final class MatroskaExtractor implements Extractor {
     }
 
   private void writeSSASample(Track track) {
-    StringBuffer s = new StringBuffer();
-    if(track.ssaHeader != null) {
-        // header contains the original format but the Matroska encoder changes this.
-        SSADecoder.writeMangledHeader(s, track.ssaHeader);
-    }
-    SSADecoder.buildDialogue(s, track.ssaSample, blockDurationUs);
-    ParsableByteArray out = new ParsableByteArray(s.toString().getBytes());
+    String s = SSADecoder.buildDialogue(track.ssaSample, blockDurationUs);
+    ParsableByteArray out = new ParsableByteArray(s.getBytes());
     track.output.sampleData(out, out.limit());
     sampleBytesWritten += out.limit();
   }
@@ -1382,7 +1377,6 @@ public final class MatroskaExtractor implements Extractor {
     public boolean flagForced;
     public boolean flagDefault = true;
     private String language = "eng";
-    public byte[] ssaHeader = null;
     public String ssaSample = null;
 
     // Set when the output is initialized. nalUnitLengthFieldLength is only set for H264/H265.
@@ -1504,7 +1498,7 @@ public final class MatroskaExtractor implements Extractor {
           break;
         case CODEC_ID_ASS:
           mimeType = MimeTypes.TEXT_SSA;
-          ssaHeader = codecPrivate;
+          initializationData = Collections.singletonList(codecPrivate);
           break;
         case CODEC_ID_VOBSUB:
           mimeType = MimeTypes.APPLICATION_VOBSUB;
@@ -1548,8 +1542,7 @@ public final class MatroskaExtractor implements Extractor {
             Format.NO_VALUE, initializationData, language, drmInitData);
       } else if (MimeTypes.TEXT_SSA.equals(mimeType)) {
         format = Format.createTextSampleFormat(Integer.toString(trackId), mimeType, null,
-              Format.NO_VALUE, selectionFlags, language, drmInitData);
-        output.track(number).sampleData(new ParsableByteArray(codecPrivate), codecPrivate.length);
+              Format.NO_VALUE, initializationData, selectionFlags, language, Format.NO_VALUE, drmInitData, Format.NO_VALUE);
       } else {
         throw new ParserException("Unexpected MIME type.");
       }

library/src/main/java/com/google/android/exoplayer2/text/SubtitleDecoderFactory.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.text;
 
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.text.cea.Cea608Decoder;
+import com.google.android.exoplayer2.text.ssa.SSADecoder;
 import com.google.android.exoplayer2.text.subrip.SubripDecoder;
 import com.google.android.exoplayer2.text.ttml.TtmlDecoder;
 import com.google.android.exoplayer2.text.tx3g.Tx3gDecoder;
@@ -24,6 +25,8 @@ import com.google.android.exoplayer2.text.webvtt.Mp4WebvttDecoder;
 import com.google.android.exoplayer2.text.webvtt.WebvttDecoder;
 import com.google.android.exoplayer2.util.MimeTypes;
 
+import static android.R.attr.mimeType;
+
 /**
  * A factory for {@link SubtitleDecoder} instances.
  */
@@ -75,10 +78,15 @@ public interface SubtitleDecoderFactory {
         if (clazz == null) {
           throw new IllegalArgumentException("Attempted to create decoder for unsupported format");
         }
+        if(clazz == SSADecoder.class) {
+          return clazz.asSubclass(SubtitleDecoder.class).getConstructor(byte[].class)
+                  .newInstance(format.initializationData.get(0));
+        }
         if (clazz == Cea608Decoder.class) {
           return clazz.asSubclass(SubtitleDecoder.class).getConstructor(String.class, Integer.TYPE)
               .newInstance(format.sampleMimeType, format.accessibilityChannel);
-        } else {
+        }
+        else {
           return clazz.asSubclass(SubtitleDecoder.class).getConstructor().newInstance();
         }
       } catch (Exception e) {

library/src/main/java/com/google/android/exoplayer2/text/ssa/SSADecoder.java

@@ -11,7 +11,9 @@ import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 
+import static android.R.attr.data;
 import static android.R.attr.subtitle;
+import static android.R.attr.x;
 
 /**
  * Created by cablej01 on 26/12/2016.
@@ -58,21 +60,33 @@ import static android.R.attr.subtitle;
     than the previous one, the value passed to getCues will go down.
  */
 
-
+/**
+ * A {@link SimpleSubtitleDecoder} for ASS/SSA.
+ */
 public class SSADecoder extends SimpleSubtitleDecoder {
     private static final String TAG = "SSADecoder";
-    private static String defaultDialogueFormat = "Start, End, Layer, Style, Name, MarginL, MarginR, MarginV, Effect, Text";
+    private static String defaultDialogueFormat = "Start, End, ReadOrder, Layer, Style, Name, MarginL, MarginR, MarginV, Effect, Text";
     private static String defaultStyleFormat = "Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding";
     private String[] dialogueFormat;
     private String[] styleFormat;
     private Map<String,Style> styles = new HashMap<>();
 
+// 0,0,Watamote-internal/narrator,Serinuma,0000,0000,0000,      ,The prince should be with the princess.
+//  , ,style                     ,name    ,L   ,R,   V   ,Effect, text
     public SSADecoder() {
         super("SSADecoder");
         dialogueFormat = parseKeys(defaultDialogueFormat);
         styleFormat = parseKeys(defaultStyleFormat);
     }
 
+    public SSADecoder(byte[] header) {
+        super("SSADecoder");
+        styleFormat = parseKeys(defaultStyleFormat);
+        decodeHeader(header, header.length);
+        // put back the Matroska format
+        dialogueFormat = parseKeys(defaultDialogueFormat);
+    }
+
     /**
      * Decodes data into a {@link SSASubtitle}.
      *
@@ -183,22 +197,8 @@ public class SSADecoder extends SimpleSubtitleDecoder {
         return result;
     }
 
-    public static void writeMangledHeader(StringBuffer s, byte[] data){
-        // header contains the original format but the Matroska encoder changes this.
-        // we won't need anything after the [Events] line
-        try {
-            String header = new String(data, "UTF-8").split("\\[Events]")[0];
-            s.append(header);
-        }
-        catch (UnsupportedEncodingException e) {
-            // we know this can't happen
-        }
-        s.append("[Events]\n");
-        s.append(defaultDialogueFormat);
-        s.append("\n");
-    }
-
-    public static void buildDialogue(StringBuffer s, String data, long durationUs) {
+    public static String buildDialogue(String data, long durationUs) {
+        StringBuffer s = new StringBuffer();
         s.append("Dialogue: ");
         s.append(SSADecoder.formatTimeCode(0)); // blockTimeUs
         s.append(",");
@@ -210,6 +210,7 @@ public class SSADecoder extends SimpleSubtitleDecoder {
         s.append(",");
         s.append(data);
         s.append("\n");
+        return s.toString();
     }
 
     public static String formatTimeCode(long tc_us) {

library/src/main/java/com/google/android/exoplayer2/text/ssa/SSASubtitle.java

@@ -11,6 +11,8 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
+import static android.R.attr.start;
+
 /**
  * Created by cablej01 on 26/12/2016.
  */
@@ -91,7 +93,8 @@ public class SSASubtitle implements Subtitle {
         String effect = ev.get("effect");
         String text = ev.get("text").replaceAll("\\\\N", "\n");
         String simpleText = text.replaceAll("\\{[^{]*\\}", "");
-        Cue cue = new SSACue(text, style, layer, effect);
+        //Cue cue = new SSACue(text, style, layer, effect);
+        Cue cue = new Cue(simpleText);
         long start = SSADecoder.parseTimecode(ev.get("start"));
         cueTimesUs.add(start);
         cues.add(cue);